Brennan: "You say that neither government nor society should regulate or control actions unless they cause harm to others."
Mill: "Correct."
Brennan: "So, what you mean by that is so long as someone claims an action--such as writing an op-ed criticizing their philosophy of gender identity--harms them, then the action should be regulated heavily by society or government."
Mill: "Uh, no, that doesn't follow."
Brennan: "Wait, why not?"
Mill: "Well, for one, anyone can claim they are harmed by anything. We can't just let individual people decide by fiat that they were harmed. A principle like that would surely be abused. I mean, if all it takes for you to be able to assert control over others is that you were harmed by them, people will claim to be harmed all the time. Human beings are pretty crappy and will generally take advantage of structures of power for their own benefit. Indeed, there is overwhelming evidence that this is how people behave. A church may be created for the purpose of saving souls, but give it 10 years and its new purpose becomes amassing wealth and real estate. You can't trust people--whether in social mobs, bureaucracies, or in governments--with much power. That's one of the big reasons I oppose paternalism, you may recall, if you read the second half of that book."
Brennan: "But suppose they could be trusted, would that be enough? And suppose it did cause real harm by some objective standard."
Mill: "Well, no. The other problem is that you are confusing a necessary condition with a sufficient condition. I'm saying that we should tolerate anything people do that doesn't harm others. But I'm not saying that if something does harm others, it should therefore automatically be subject to any, let alone significant, social or political regulation."
Brennan: "Why not?"
Mill: "I mean, to simplify the argument I make in that book, it comes down to this: When we decide what level of freedom people should have, and how much we should tolerate, we should draw the line where doing so produces the most overall social progress and overall best living conditions for people. High tolerant, risk-taking societies produce great social, political, scientific, artistic, and cultural progress, while heavily moralizing, indignant, puritanical, risk-averse, and mobbish societies do not. Tolerant societies make people flourish, intolerant societies do not. I realize that's an empirical argument and requires empirical proof, but I think history and economic analysis rather clearly demonstrates I'm right."
Brennan: "Can you give me an example of a harm that we should tolerate?"
Mill: "Take one from economics. If a competitor comes along who builds a better mousetrap, she might put your mousetrap company out of business. It's plausible to say that you've been harmed--probably far more than a person would be harmed by, say, allowing a conservative speaker to come to campus, a speaker the person is free to ignore. So, imagine we said that in order to prevent harm, we never allow people to outcompete each other in the market. What do we get? Stagnation, poverty, rent seeking, and a political system run by insiders who control the anti-competitive regulations for their own benefit at the expense of everyone else. See the medieval guild systems, for example. We all are better off in a system where such competition is allowed, even though each of us would prefer that we, and we alone, be immunized and protected against such competition. Similarly, overall, we each benefit greatly from living in liberal, open, tolerant cultures, even though we each selfishly might wish to crush and destroy those who have ideas and beliefs we despise."
Brennan: "People are much less racist, ethnocentric, sexist, and so on today then back when you were writing, say, The Subjection of Women. Do you think we're a more tolerant society?"
Mill: "Yes, for sure. But at the same time, we should be careful not to credit people with being tolerant when they really aren't. Most people today are not very tolerant overall, even if they are more tolerant than most people were through most of history. Toleration means putting up with things you dislike and disapprove of. For instance, Jay, do you disapprove of homosexuality?"
Brennan: "No, not at all. I think there is no moral difference between heterosexual or homosexual sex, or really any consensual sex among adults."
Mill: "Then you can't really be said to tolerate these actions, because you don't disapprove of them. It's a bit like saying you are tolerant of people using red toothbrushes. Toleration means putting up stuff you dislike and disapprove of. In contrast, if an evangelical Christian thinks homosexuality is sinful but puts up with it, doesn't harass gay people, and generally leaves them alone, that's tolerance. So, what are some things you disapprove of?"
Brennan: "Illiberalism, for one. Liberalism is the correct theory of justice. I also, frankly, tend to think that non-liberals are almost universally motivated by a will to power and that their putative reasons for illiberalism are a cover for their self-interested actions."
Mill: "Ok, so as a liberal, you have to tolerate illiberal people. Here, read this FAQ to understand what that means. Toleration is an extremely demanding principle, and most people don't live up to it."